Demographic Analysis: 2020-2025 Survey Comparison

Age-Gender Distribution Analysis and Weighting Assessment

1 Executive Summary

This report analyzes demographic shifts between our 2020 and 2025 surveys, focusing on age-gender distributions by examining whether weighting the 2025 data to match the 2020 demographic composition would improve comparability between survey waves.

Key Findings:

• 2020 sample: 2,606 respondents
• 2025 sample: 2,437 respondents
• Demographic composition differences detected between survey waves
• Statistical weighting analysis performed to assess need for adjustments

2 Dataset Overview

2.1 Sample Composition

Sample Composition Overview

Dataset	Sample Size	Women (%)	Men (%)	Nonbinary (%)
2020 Survey	2606	82.4	17.5	0.1
2025 Survey	2437	85.3	14.3	0.4

2.2 Age-Gender Cross-Tabulations

2020 Age-Gender Distribution (Counts)

Age Group	Men	Nonbinary	Women
Under 25	7	0	38
25-29	23	0	164
30-34	38	0	271
35-39	52	1	325
40-44	51	0	292
45-49	58	1	263
50-54	56	1	266
55-59	56	0	268
60-64	65	0	172
65 or older	47	0	72

2025 Age-Gender Distribution (Counts)

Age Group	Men	Nonbinary	Women
Under 25	4	2	38
25-29	18	0	149
30-34	23	1	201
35-39	54	1	297
40-44	45	0	343
45-49	49	2	304
50-54	42	1	263
55-59	46	0	219
60-64	20	2	159
65 or older	37	1	91

3 Weighting Analysis

3.1 Methodology

We calculated weights to adjust the 2025 data to match the 2020 demographic distribution:

Weight Formula: Weight = (2020 Proportion) ÷ (2025 Proportion)

This approach allows us to examine what the 2025 results would look like if the sample had the same age-gender composition as 2020.

Data Quality Note: Some age-gender combinations exist in 2025 but have zero representation in 2020. These cases receive zero weights and are excluded from the weighted analysis.

Age-Gender Combinations in 2025 with Zero 2020 Representation

Age Group	Gender	2025 Count	2020 Count
25-29	Nonbinary	0	0
30-34	Nonbinary	1	0
40-44	Nonbinary	0	0
55-59	Nonbinary	0	0
60-64	Nonbinary	2	0
65 or older	Nonbinary	1	0
Under 25	Nonbinary	2	0

4 Visual Analysis

4.1 Distribution Comparison

Age-Gender Distribution Across All Datasets

4.2 Gender Distribution Overview

Overall Gender Distribution Comparison

4.3 Demographic Shift Analysis

Demographic Changes Between 2020 and 2025

Magnitude of Demographic Changes by Group

4.4 Impact of Weighting

Effect of Weighting on 2025 Distribution

5 Statistical Summary

Statistical Summary

Metric	Value
2020 Sample Size	2,606
2025 Sample Size	2,437
2025 Effective Sample Size (Weighted)	2,412
Total Demographic Change	15.3 percentage points
Largest Single Group Change	2.9 percentage points
Cases Excluded from Weighting	31

6 Recommendations

6.1 Weighting Decision Analysis

Based on our demographic shift analysis, here are our findings and recommendations:

Key Metrics:

• Total demographic change: 15.3 percentage points
• Largest single group change: 2.9 percentage points
  
• Sample retention after weighting: 98.7%

Recommendation: Use Weighted Data

Reason: Large demographic shifts detected (>10 percentage points total change)

The substantial differences in age-gender composition between 2020 and 2025 suggest that weighting will significantly improve comparability between survey waves.